Wire stop and wire guide in terminals and connectors

ABSTRACT

An electrical terminal for use in conjunction with thinly insulated wires and cables is disclosed. The terminal has funnel means therein to guide the conductors of the wires into place in the terminal wire barrels. The terminal has means therein to limit the forward insertion travel of the wire to assure that no wire insulation enters the wire barrel area. The funnel means provides strain relief means in a crimped connection where the wire joins the terminal.

United States Patent [72] Inventor Karl Lester Kaylor Middletown, Pa.[21] Appl. No. 817.396 [22] Filed Apr. 18. 1969 [45] Patented Sept. 14.1971 [73] Assignee AMP Incorporated Harrisburg, Pa.

[54] WIRE STOP AND WIRE GUIDE 1N TERMINALS AND CONNECTORS 7 Claims, 5Drawing Figs.

[52] U.S. Cl 339/223, 339/276 [51] Int. Cl H0lr 11/12, HOlr 11/00 [50]Field of Search 339/103, 205, 217, 101. 276; 174/84, 87; 287/85 5 6]References Cited UNITED STATES PATENTS 2,078,051 4/1937 Bemdt 339/2552,405,] 1 1 8/1946 Carlson et a1 339/276 X 2,618,684 11/1952 Bergan339/276X 2,904,619 9/1959 Fomey .lr. 339/223 X 3,281,524 10/1966 LynchJr. et a1. 339/223 3,312,929 4/1967 Shannon 339/276 X 3,356,987 12/1967Gillespie 339/276 X Primary Examiner-Richard E. Moore Anorne vsCurtis,Morris and Safiord, Marshall M.

Holcombe, William Hintze, William .1. Keating, Frederick W. Raring, JohnR. Hopkins, Adrian J. LaRue and Jay L. Seitchik ABSTRACT: An electricalterminal for use in conjunction with thinly insulated wires and cablesis disclosed. The terminal has funnel means therein to guide theconductors of the wires into place in the terminal wire barrels. Theterminal has means therein to limit the forward insertion travel of thewire to assure that no wire insulation enters the wire barrel area. Thefunnel means provides strain relief means in a crimped connection wherethe wire joins the terminal.

PATENTEUSEPMIHTI 3.605.077

' M/VE/VTU/i' I I Karl Lester Kaylor K CD er WIRE STOP AND WIRE GUIDE INTERMINALS AND CONNECTORS This invention relates to electrical terminalsof the type used to connect lead wires to electrical terminals of thetype used to connect lead wires to electrical components. Moreparticularly, the invention relates to wire guides and wire stops inelectrical terminals for properly locating the lead wires relative tothe terminal wire barrels. A tenninal according to this invention hasmeans to support the wire where it joins the terminal so as to preventundue bending stresses on the wire which normally concentrate at thatpoint. This support means is disclosed in US. Pat. No. 2,405,1 l l, andcomprises a metal sleeve fitted over the terminal barrel.

To illustrate the utility of the present terminal, it may be pointed outthat lead wires or cables having an extremely thin insulation cover madeof plastic are difficult to terminate in the terminal disclosed in theabove-mentioned patent. The thin insulation sometimes permits aprestripped wire to be overinserted into the wire barrel of theterminal. This results in a poorly crimped connection because wireinsulation enters the terminal wire barrel. Also, a crimped connectionwill have little or no strain relief characteristics where the wirejoins the terminal. Thinly insulated wires are becoming more useful,particularly in automotive and aircraft applications.

It is therefore an object of this invention to obviate the aboveundesirable characteristics by providing a tapered ferrule insert meansin an insulation support of a terminal.

Another object is the provision of wire stop means to prevent a wirefrom being overinserted into a wire barrel of a terminal.

A further object is to provide wire guide means to gather wire strandsand guide them into a terminal wire barrel.

Still another object is to provide strain relief means to relieve unduebending stresses on a thinly insulated wire where the wire joins aterminal.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon reading of the followingdetailed description when taken in conjunction with the drawings inwhich there is shown and described illustrative embodiments of theinvention; it is to be understood, however, that these embodiments arenot intended to be exhaustive now limiting of the invention but aregiven for purposes of illustration in order that others skilled in theart may fully understand the invention and the principles thereof andthe manner of applying it in practical use so that they may modify it invarious forms, each as may be best suited to the conditions of aparticular use.

In the drawings:

FIG. 1 is a perspective view showing tapered ferrules in strip form;

FIG. 2 is a cross-sectional and exploded view of a terminal;

FIG. 3 is a cross-sectional view showing a terminal assembled with awire in place;

FIG. 4 is a cross-sectional view of FIG. 3 after it has been crimped;and

FIG. 5 is a fragmentary cross-sectional view of an alternate embodimentofFIG. 3.

Referring to FIGS. 2-4, an electrical terminal T according to thepresent invention comprises a terminal connector section 2 of theapertured-tongue type including a wire barrel section 4 coextensivetherewith. Connector section 2 may, of course, take any desirable form.A thin metal insulation support sleeve 6 surrounds and frictionallyengages barrel section 4 and extends from the wire entry end of barrelsection 4. An insulation sleeve 8 of suitable dielectric material ispreferably bonded or secured to support sleeve 6 constituting apreinsulated electrical terminal. The inside surface of barrel section 4is preferably serrated and the entrance thereto is beveled. The sectionof sleeve 6 not engaging barrel section 4 is larger in diameter than thesection of sleeve 6 engaging barrel section 4 and a margin of the largerdiameter section is folded inwardly into engagement with the insidesurface of sleeve 6. A serrated edge 7 is provided along the doublethickness area.

Referring to FIGS. 1-3, wire stop and wire guide means may be defined bya conically shaped ferrule or funnel F which is generally made of metalsimilar to sleeve 6. The large end of funnel F has a flange defined byan out-turned lip 10 which effectively snaps into place behind theserrated edge 7 in sleeve 6. The small end 12 of funnel F has itsopening slightly enlarged by thinning the wall thickness, as at 14.Small end 12 is disposed to abut the tapered entrance to barrel section4 such that a short length of the end 12 enters the barrel section whena funnel is snapped into place in a terminal. This allows a conductor topass through the small opening and the opening of the wire barrelsection without catching or snagging at the opening thereof. End 12 offunnel F in entering wire barrel section 4 when the funnel is assembledinto a terminal T provides an arrangement that holds the funnel openingin axial alignment relative to the opening of barrel section 4, and thisserves to effectively guide a conductor into wire barrel section 4.

Referring particularly to FIG. 1, a series of funnels 10 are formed froma flat strip 16 of metal by conventional metaldrawing techniques.Funnels 10 remain attached to strips 16 by small connecting straps 18.During automatic assembly of terminals, strips 16 serve to carry funnels10 to the terminals whereat they are severed from strips 16 and insertedinto terminais T.

Referring to FIG. 3, a wire W is stripped of a length of its thininsulation cover CO, and the exposed bare conductor CD is inserted intoa terminal T. During entry, the ends of the conductor are gathered andpointed by funnel F. When the conductor CD is fully inserted into barrelsection 4, the severed edge E of the insulation cover CO engages thewalls of funnel F. This arrangement limits the forward insertion travelof the wire W into the terminal R and properly positions the conductorCD in barrel section 4 so that when it is crimped an effective crimp isattained.

Notice particularly in FIG. 3 that the inside diameter of the small end12 of funnel F is only slightly larger than the diameter of conductorCD. This arrangement assures that extremely thin insulation on a wire Wwill not enter wire barrel section 4.

Upon crimping, barrel section 4 is swaged onto conductor CD for amechanical and electrical connection, as shown in FIG. 4.Simultaneously, a crimp onto the enlarged end of insulation sleeve 8will swage funnel F, support sleeve 6 and insulation sleeve 8 onto theinsulation cover C0 of wire W. This arrangement provides strain reliefmeans for thinly insulated wires. Wires with slightly larger insulationcovers CO may be used in the present invention, in which cases, thesevered edge E of wires W bottom in a larger diameter section of funnelF.

Referring to FIG. 5 wherein terminal Ta which is an alternate embodimentshown, a funnel Fa may be formed from an extension of support sleeve 6.Funnel Fa serves the same purpose as described above. The funnel isintegral with an inwardly folded margin of the metallic sleeve 6 andtapers to a single thickness end partially received in the end of theopening of the wire barrel 4. The end of the funnel has an opening whichis in axial alignment with the wire barrel opening.

It should be noted that funnel F may be made of plastic or othersubstantially pliable dielectric material if desired, in which cases,after crimping the funnel will become compressed around the wireinsulation CO and provide a connection which is sealed against theingress of moisture and water.

It should also be noted that solid conductor wire may be used withoutdeparting from the scope of the invention.

Connectors, not shown, for joining two wires may utilize the concepttaught in the present invention in which case terminal connector section2 is eliminated, and wire-receiving means and funnel means areincorporated into each end of the connector.

It will therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiments of the invention, which are shown anddescribed herein, are intended as merely illustrative and not asrestrictive of the invention.

The invention is claimed in accordance with the following:

1. In an electrical terminal, the combination comprising: anelectrically conductive wire barrel having an opening adapted to receivetherethrough a wire conductor of an electrical wire, a metallic sleevecontaining said barrel, an insulation sleeve surrounding said metallicsleeve, said metallic sleeve extending beyond an end of said barrel andhaving an inwardly folded margin portion in spaced relationship fromsaid wire barrel and, said margin portion generally of annularconfiguration and in engagement with the inside of said metallic sleeve,and a freely insertable funnel of resilient material inserted within andpast said annular margin and into the inside of said metallic sleeve,said funnel being retained within said sleeve and in engagement againstan edge of said inwardly folded margin and the end of said wire barrel.

2. The structure as recited in claim 1, wherein said funnel tapers to athin wall portion defining an opening, said thin wall portion engagedagainst said wire barrel end, and said thin wall opening and said wirebarrel opening being axially aligned.

3. The structure as recited in claim 2, wherein, said funnel is ofresilient material and a large end of said funnel has an outer lip whichis initially resiliently compressible upon said insertion past saidinwardly folded margin portion and subsequently resiliently expandableand in engagement against the edge of said margin portion, said funnelbeing located between and in engagement against said margin portion edgeand said wire barrel end.

4. The structure as recited in claim 3, wherein, said funnel is ofresilient material and includes a large end with an outer lip which isinitially resiliently compressible upon insertion of the funnel pastsaid inwardly folded margin, said lip additionally being resilientlyexpandable and in engagement against the edge of said inwardly foldedmargin, with said funnel located between and in engagement against saidmargin edge and said wire barrel end.

5. The structure as recited in claim 1, wherein, said funnel ispartially received in said wire barrel opening.

6. The structure as recited in claim 2, wherein, said thin wall of saidfunnel is partially received in said wire barrel opening.

7. The structure as recited in claim 1 and further including: anelectrical wire having a wire conductor end portion protruding from aninsulation layer, which wire conductor end portion is insertedinteriorly of said wire barrel with a portion of the insulation layerbeing received interiorly of said funnel and the metallic sleeve, saidwire barrel being crimped in mechanical and electrical engagement onsaid wire conductor end portion, and said metallic sleeve and saidfunnel being crimped simultaneously over said insulation layer with saidfunnel in crimped engagement with said insulation layer.

lOlOOl 0497

1. In an electrical terminal, the combination comprising: anelectrically conductive wire barrel having an opening adapted to receivetherethrough a wire conductor of an electrical wire, a metallic sleevecontaining said barrel, an insulation sleeve surrounding said metallicsleeve, said metallic sleeve extending beyond an end of said barrel andhaving an inwardly folded margin portion in spaced relationship fromsaid wire barrel and, said margin portion generally of annularconfiguration and in engagement with the inside of said metallic sleeve,and a freely insertable funnel of resilient material inserted within andpast said annular margin and into the inside of said metallic sleeve,said funnel being retained within said sleeve and in engagement againstan edge of said inwardly folded margin and the end of said wire barrel.2. The structure as recited in claim 1, wherein said funnel tapers to athin wall portion defining an opening, said thin wall portion engagedagainst said wire barrel end, and said thin wall opening and said wirebarrel opening being axially aligned.
 3. The structure as recited inclaim 2, wherein, said funnel is of resilient material and a large endof said funnel has an outer lip which is initially resilientlycompressible upon said insertion past said inwardly folded marginportion and subsequently resiliently expandable and in engagementagainst the edge of said margin portion, said funnel being locatedbetween and in engagement against said margin portion edge and said wirebarrel end.
 4. The structure as recited in claim 3, wherein, said funnelis of resilient material and includes a large end with an outer lipwhich is initially resiliently compressible upon insertion of the funnelpast said inwardly folded margin, said lip additionally beingresiliently expandable and in engagement against the edge of saidinwardly folded margin, with said funnel located between and inengagement against said margin edge and said wire barrel end.
 5. Thestructure as recited in claim 1, wherein, said funnel is partiallyreceived in said wire barrel opening.
 6. The structure as recited inclaim 2, wherein, said thin wall of saId funnel is partially received insaid wire barrel opening.
 7. The structure as recited in claim 1 andfurther including: an electrical wire having a wire conductor endportion protruding from an insulation layer, which wire conductor endportion is inserted interiorly of said wire barrel with a portion of theinsulation layer being received interiorly of said funnel and themetallic sleeve, said wire barrel being crimped in mechanical andelectrical engagement on said wire conductor end portion, and saidmetallic sleeve and said funnel being crimped simultaneously over saidinsulation layer with said funnel in crimped engagement with saidinsulation layer.